Research Methods Experimental Design

UWSP PSYC 200 Final Exam

Independent Variable

The manipulated variable

Dependent Variable

The measured variable

Confounding Variable

An unmeasured variable

Quasi Experiment

Looks like a true experiment but fundamentally is not, often becomes a chicken or egg problem

Within-Subjects Design

The subjects are exposed to all conditions or independent variables

Between-Subjects Desing

the subjects are exposed to only one condition of the experiment

Factorial Design

When an experiment has more than 1 independent variable so the influence of each variable can be calculated and effects and combinations can be assessed

Null Hypothesis

A statement suggesting that there is no effect, significance, or relationship between variables

Research Hypothesis

A statement suggesting there is an effect, significance, or relationship between variables

Experimental Group

The group where conditions are tested or changed

Why is assignment important?

It accounts for differences between subjects

Statistical Significance

The probability of results being due to chance

Statistical Significance Decision

A declaration that the difference is not due to chance, AKA rejecting the null hypothesis

Hypothesis Testing

Rejects chance as the best explanation for an experiment’s results, AKA rejecting the null hypothesis

Random Assignment

should be used when the treatment or conditions are the only change between groups

Main Effect

Describes the relationship between the independent and dependent variables. The larger the factorial design, the more to describe

Interaction

when the relation between the IV and DV is dependent on the levels of another IV

Clues of a possible interaction

crossing, non-parallel lines on a line graph and if you need the second IV to describe the results. An “it depends” statement

Mixed Factorial Desing

Has both a between-subjects and within-subjects design